1. Field of the Invention
The present invention relates to a droplet ejection device and a method for collecting adherent liquid, and more particularly to a droplet ejection device and method for collecting adherent liquid for collecting adherent liquid adhered to a droplet ejecting face.
2. Description of the Related Art
A droplet ejection device includes, for example, an inkjet recording device that ejects droplets of ink or the like from nozzles of a recording head to record an image on a recording medium such as paper or the like. In the inkjet recording device, during ink droplet ejections, ink mist or ink leaking from the nozzles or the like may adhere on an ink droplet ejecting face near the nozzles, and the ejection directions of ink droplets may be diverted or ink droplet ejection itself may be hindered.
Therefore, as a method for removing ink adhering to the ejection face, it has been considered to wipe the ejection face. However, in order to perform wiping operation, recording operation recording an image with ink droplets must be temporarily stopped, and printing speed is reduced. As a method for collecting adherent ink adhered to the ejection face without interrupting recording operation, it has been proposed in Japanese Patent Application Laid-Open (JP-A) No. 2008-254279 to form a collecting hole in the ejection face and collect adherent liquid adhered to the ejection face through this collecting hole.
In the liquid ejection head of JP-A No. 2008-254279, the collecting hole is in communication with an ink chamber, and adherent ink collected through the recovery hole is collected into the chamber. In addition, to guide the adherent ink into the collecting hole, on a nozzle plate face (the ejection face), a non-water-repellent region is formed around the collecting hole, and a water-repellent region is formed around the non-water-repellent region.
However, adherent ink adhered to the face of the nozzle plate becomes viscous due to drying, or solidified particles, dust in the atmosphere or the like may be mingled with the adherent ink. Therefore, as in the liquid head ejection head of JP-A No. 2008-254279, if liquid that is collected is re-used, clogging of nozzles or the like may occur.
On the other hand, JP-A No. 2003-127436 discloses an inkjet recording device in which an ink collection aperture is provided in the vicinity of nozzles in an orifice plate face and an ink intake unit is provided at the ink recovery aperture via a collection path. In the above inkjet recording device, the orifice plate face is wiped and adherent ink is scraped off, and when the scraped off ink reaches the ink collection aperture, the ink is taken into the ink intake unit. In addition, a vicinity of the ink recovery aperture is given better wetting characteristics than the vicinity of the nozzles.
However, in spite of forming a non-water-repellent region around the collecting hole or improving wettability of the ink collection aperture vicinity as disclosed in JP-A Nos. 2008-254279 and 2003-127436, adherent liquid at the non-water-repellent region or region with good wetting may not be thoroughly collected. Ink not being collected hardens and, for example, solid matter scraped off by a wiping member (wiper) in a wiping operation may clog up the nozzles.